21144430232 has 8 divisors (see below), whose sum is σ = 39645806700. Its totient is φ = 10572215112.

The previous prime is 21144430157. The next prime is 21144430247. The reversal of 21144430232 is 23203444112.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1321526882 + ... + 1321526897.

Almost surely, 2^21144430232 is an apocalyptic number.

It is an amenable number.

21144430232 is a deficient number, since it is larger than the sum of its proper divisors (18501376468).

21144430232 is a wasteful number, since it uses less digits than its factorization.

21144430232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2643053785 (or 2643053781 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 26.

Adding to 21144430232 its reverse (23203444112), we get a palindrome (44347874344).

The spelling of 21144430232 in words is "twenty-one billion, one hundred forty-four million, four hundred thirty thousand, two hundred thirty-two".